Well, we lowered the pressure to 700 psi and reduced the load proportionally as well. Everything goes back to working as before, the pump easily positions the load up and down with about half load on the motor. With the higher load and proportionally higher accumulator gas pressure the motor did...
I received the Gresen (Parker) PPG series gerotor pump/motor. At 500 psi accumulator pressure required to balance the load everything is working perfect. Since I had to put the 4" cylinder version with the bi rotational Deli (Northern Hydraulics) to work I build another lift with a 2" cylinder...
The Wuxi pump's shaft seal with the added thrust washer should be ready to try early next week. As far as wear the pump will operate at with a differential pressure of less than 50 psi. As was mentioned above by 73lafuite the pressure in the accumulator increases as the cylinder retracts and...
I guess that hoping that the new and better seal has enough capacity is one way of looking at the problem though I prefer good engineering practice. Actually I am looking for a workaround to the shaft seal problem, perhaps using a bi-directional hydraulic motor of similar displacement that would...
The local pump people came up with a replacement seal that they say will support a substantially higher pressure. We'll see. If it will hold up with about 350 psi, the system should work. My original design used a screw jack to position the load while the accumulator balanced the load applied...
I swapped the bmp for a cropped jpg, sorry about the bmp. I've added a couple of elements to the system, pressure valves to observe what the heck is actually going on, and a hand bypass valve to be used when charging the acumulator. I just found out that my tech ran the accumulator pressure in...
The application is raising and lowering a 4000# vertical load approximately 20" once every 120 seconds, 10 seconds to extend 20" and 10 seconds to retract 20", 100 seconds dwell. An accumulator is charged with nitrogen to approx 320 psi to offset the load produced by the 4000# weight acting...
